I don’t have a RYTM but I do have some eurorack (without drum modules) that I sample for drums all the time. My mainstay for 909-esque kicks is a super fast exp. envelope modulating the exp. FM input of a thru-zero sine wave oscillator mixed with high frequency noise (also FM modulated by another exp. envelope) from a locked linear feedback shift register.
The hard part for me has always been timing the amp envelope properly so that enough of the low end decay gets through but not too much that it gets flabby. It’s usually a constant dance and tweaking game between the three different envelopes until I can find something that sounds good and has enough slam while still being tight.
Again, great thread, super excited to adapt some of the techniques described on my modular.
I read this three times… freaks me out more each time. You are not creating a kick my man. That will make a wormhole to another dimension!!! Dont do it!!!
It has a VCO, pitch decay envelope, amplitude envelope, noise generator and noise filter.
The recreations that I’ve seen use digital noise generated by a linear feedback shift register. (Slightly different than say a transistor noise circuit.). More like the noise in old 8 bit video games. I believe the 909 did this as well, but I haven’t found the original schematic yet.
I don’t have an AR anymore, so I can’t join in the fun. Might be able to do it on one of my synths though. I’ll give it a try if I get a few minutes.
I’ve been meaning to post this here: Came across a 909 service manual.
Not sure if it’s really Roland official but includes a lot of great block diagrams that for every sound including detailed schematics. I’m not that versed in actual synth schematics, but curious if you can glean anything from it.
That’s exactly what I was looking for. The dual 4006 CMOS shift registers confirm the digital white noise source as I mentioned above.
I’ll look over the rest of it in a bit.
I’m not sure what type of noise the AR has as it’s been a while since I had mine.
It can be done with a sample of this type of noise, the “decimator” noise on a Korg XD or Prologue, and the Analog 4 also has this type of noise. In fact the A4 might be the best thing to create a 909 kick with. (From scratch anyway). Or a modular for sure… It looks like a filter follows the noise, but I need to look more closely.
Edit: Yes, simple RC low pass filter after the noise.
So it has a typical Schmitt Trigger triangle VCO, and noise. It looks like there are a couple of clamping diodes after the triangle wave, maybe to kind of clip or round it into a semi-sine wave. Tri or sine would be fine when synthesizing.
There are three envelopes. One for pitch, one for noise, one for amplitude. These could be comined in a couple of ways to get “close enough” with two envelopes when synthesizing the kick on something else.
That’s pretty much it. It should be quite possible on the AR/A4 or probably most full featured mono-synths.
I’m glad I’ve found this thread.
I have a TR-909 and I might sell it to get something else such as the RYTM. Very good sound in the video and links I’ve seen in here.
I found using a lowpass filter set to like 120ish with a boosted resonance helped the noise section pop a bit more when I was trying to get a 909ish snare. Think like the technique of using a HP filter to boost bass but in reverse. lots of interesting techniques here makes me miss my rytm. IIRC the Noise is digital on the A4/AR so that might work to your advantage when synthesizing a 909.
I have been working on 909 sounds starting with the kick. I don’t have it nailed, but I did fix/figure one thing out that’s been bothering me. All the ar2 kick sounds have crazy low end, and sizzly top end, but they miss a lot of the low mid that many 909 kick sounds feature prominently, and I could not for the life of me feel fully satisfied with any kick sound.
I am really happy now, after having messed with the peak filter type. Adding resonance in that low mid frequency range really added a lot of body to the sound, rather than just the ultra low, boxy, clacky kind of sound I was getting without it.
Here is my 909 snare attempt. I find that my best results are kind of like the opposite of the kick drum. Where the kick was missing low mid resonance and tone, the snare has too much tone. Using the “band stop” filter pulls out some of those unnecessarily pitchy overtones and leaves a much more natural snare drum sound that has a nice mix of body and noise, without the tonal intrusion.
Cheers, welcome aboard! I am happy this has helped a little.
It’s really been a game changer for me. I went from being a little bit unhappy with all of the kick sounds I was getting (again, too boxy for my tastes) to being able to get an endless amount of different sounding kicks I am really happy with.
lots of interesting techniques here makes me miss my rytm. IIRC the Noise is digital on the A4/AR so that might work to your advantage when synthesizing a 909.
